GB2170109A

GB2170109A - Anaesthesia machine

Info

Publication number: GB2170109A
Application number: GB08502251A
Authority: GB
Inventors: Alan Michael Fiske
Original assignee: BOC Group Ltd
Current assignee: BOC Group Ltd
Priority date: 1985-01-30
Filing date: 1985-01-30
Publication date: 1986-07-30
Also published as: GB8502251D0; GB2170109B

Abstract

Gas regulators 12 are attached to manifold blocks only by bolts 20. When detaching the regulators, it is necessary only to unscrew the bolts 20. There are no high pressure connections to the regulators. A medical gas passes firstly directly from the manifold block through the regulator and then returns directly to the manifold block before leaving the manifold block at an outlet port. <IMAGE>

Description

SPECIFICATION Improved anaesthesia machine The present invention relates to anaesthesia machines for delivering medical gases to a patient.

Anaesthesia machines are known which us a "modular" concept, that is, a concept of using individual manifold blocks for each medical gas rather than a multiplicity of high pressure lines and connections. However, in these known machines, some high pressure connections are still used, particularly where gas regulators are employed to control medical gas flow through a manifold block.

It is an aim of the present invention to provide an anaesthesia machine in which all high pressure connections to gas regulators are eliminated with a subsequent easy replacement of such regulators.

According to the present invention, an anaesthesia machine comprises at least one manifold block and an associated gas regulator detachably assembled thereto in a gas tight manner by means only of screw threaded attachment means such that, in use, a medical gas first passes directly from the manifold block through the regulator and then returns directly to the manifold block before leaving the manifold block at an outlet port.

Preferably, at the interface between the manifold block and the regulator, seals are provided which surround the flowpath of the medical gas as it passes from the manifold block to the regulator and returns again to the manifold block.

For the avoidance of doubt throughout this specification, reference to "gas" includes "gas mixtures" such as air where applicable.

An embodiment of the invention will now be described, by way of example, reference being made to the Figures of the accompanying diagrammatic drawings in which: Figure 1 is an exploded perspective view of an anaesthesia machine; Figure 2 is an exploded perspective view of a manifold block and a detachable regulator forming part of the anaesthesia machine of Figure 1; and Figure 3 is a side sectional view of the manifold block and detachable regulator of Figure 2.

As shown in Figure 1, an anaesthesia machine 1 includes a plurality of manifold blocks 2, 4, 6 and 8, each associated with a different gas or gas mixture.

Manifold block 2 is associated with oxygen; manifold block 4 is associated with nitrous oxide; manifold block 6 is associated with air and manifold block 8 is associated with carbon dioxide.

The various gases enter and leave their associated manifold blocks from gas sources and leave said manifold blocks for passage towards flowmeters, mixing chambers and vaporisers in a manner known in the art.

Referring also to Figures 2 and 3, detachably attached to each manifold block is at least one gas regulator 12. For simplicity, only one manifold block 2 and two associated gas regulators 12 are illustrated but it is to be understood that each manifold block 2, 4, 6 and 8 has at least one gas regulator associated with it.

Each gas regulator 12 is detachably assembled to the manifold block 2 by screw threaded attachment means in the form of bolts 20. At the interface between the manifold block 2 and the regulators 12, seals 22 are provided which surround passages 24, 26 in each gas regulator 12 forming part of a flow passage for oxygen as it passes directly from the manifold block 2 through an individual regulator 12 and returns directly to the manifold block.

The manifold block 2 has passages 30, 32 also forming part of the flowpath for oxygen which passages complement respectively the passages 24 and 26 in the regulators 12.

In use, oxygen flows through passage 30 in the manifold block 2 and then directly into a regulator passage 24 and hence into the regulator passage 26 and finally directly back into the manifold block passage 32. The gas exits from the manifold block at outlet 34.

Preferably, the seals 22 are BODOK seals, that is, seals in which an inner ring of resilient material such as rubber is bonded to an outer mtallic ring.

BODOK seals are robust and can withstand greater pressures than the equivalent diameter of ordinary O-ring seals. Further, one of the BODOK seals can be used as a location for the regulator 12 when assembling it to the manifold block 2. The location is achieved because the seal (see Figure 3) is retained in a recess in the regulator 12 and the plain diameter of a non-return valve 40 extending outwards from the manifold block 2 passes through the rubber ring of the seal and, having a tight fit on this diameter, is held quite firmly allowing the regulator to swing about this point to align the fixing holes for accepting bolts 20.

It will be apparent that if the or each gas regulator 12 needs to be removed for servicing, calibration or replacement, it is only necessary to unscrew the bolts 20 which is a relatively simple, quick and foolproof operation. In the past, it has been necessary also to release from the gas regulators high pressure connections which were difficult to reach and time consuming to undo.

Claims

1. An anaesthesia machine comprising at least one manifold block and an associated gas regulator detachably assembled thereto in a gas tight manner by means only of screw threaded attachment means such that, in use, a medical gas first passes directly from the manifold block through the regulator and then returns directly to the manifold block before leaving the manifold block at an outlet port.

2. An anaesthesia machine as claimed in claim 1, in which, at the interface between the manifold block and the regulator, seals are provided which surround the flowpath of the medical gas as it passes from the manifold block to the regulator and returns again to the manifold block.

3. An anaesthesia machine as claimed in claim 1 or 2 in which the screw threaded attachment means are bolts.

4. An anaesthesia machine constructed and ar ranged substantially as hereinbefore described with reference to and as illustrated in the Figures of the accompanying drawings.